In an electrical power distribution system with multiple branch circuits, it is desirable to monitor each branch circuit for a multitude of reasons including load management, power quality analysis, and tenant metering. Historically, each branch circuit had to be monitored by an individual meter which created redundancy in multiple meters, wires, memory, processors, communication ports, etc. High Density Metering (HDM) systems were developed to monitor power distribution systems with multiple branch circuits in a single meter and eliminate much of the redundancy. As a result, HDMs provide significant savings in material, space, and installation costs.
In designing an HDM system, the goal is to design a meter that efficiently monitors multiple branch circuits and is accurate, versatile, convenient and economical. HDMs typically have a single voltage input that is common to the power distribution system and a current input from each phase of each branch circuit being monitored. An HDM monitors the voltage and current inputs over a period of time and calculates real-time readings, demand readings, energy readings, and power analysis values. Even though all HDMs monitor the same inputs, there is a great deal of variety in the way in which HDM systems acquire data, transmit data internally, and process the data.
To design a versatile HDM, it is important to be able to acquire data from a variety of branch circuit configurations. HDMs typically only monitor branch circuits that are all the same configuration. This is problematic when a single distribution panel supplies power to a variety of single and/or poly-phase loads.
Additional limitations surrounding HDMs stem from an HDM's ability to transfer and process the acquired data. An HDM is limited in the number of branch circuits that can be monitored by its ability to transfer and/or process data. Deciding what internal communication system or processors to use in order to monitor a maximum number of circuits must be carefully balanced with the cost of implementing such components. The cost of implementation will not only include the cost of the communication system and processor, but other design considerations that will be affected, such as memory requirements, wiring, and the overall size of the HDM.
To achieve the goals of designing an HDM, it is important to have an efficient method of acquiring, transmitting, and processing data within an HDM. The present invention is directed to satisfying this and other needs.